基坑设计土体参数的正确选取直接影响支护结构的位移和内力计算结果，特别是土体水平抗力比例系数m值对支护结构位移的影响最为显著。结合基坑开挖工程实例，通过材料性状与基坑开挖施工过程的平面有限差分法模拟，模拟计算基坑分布开挖过程结构的水平位移；通过分析诸多土体参数对基坑支护结构水平位移的影响程度，确定杨氏模量作为位移反分析所需获取的参数，构建实测位移与模拟计算位移之间的目标函数，反分析给出各层土的杨氏模量；基于弹性地基梁法推导的m值与杨氏模量的关系，给出反映实际侧向变形特性各层土的m值。研究结果为基坑工程设计参数的合理确定提供了一定理论参考依据，对有效控制基坑位移与变形具有重要的实践意义。

Reasonable soil parameters directly affect the displacement and internal force calculation results of the supporting structure in foundation pit design. Especially the proportional coefficient m of horizontal resistance has the most pronounced influence on the displacement of the supporting structure. Based on an engineering case of foundation excavation, the characters of materials and process of foundation excavation were simulated by the plane finite difference method, so that the horizontal displacement of the supporting structure for the excavation was simulated and calculated. Through analysis of the influence of soil parameters on the horizontal displacement of the supporting structure, it was determined that Young's modulus was the parameter to be obtained for the back-analysis of displacement. The objective function between measured displacement and simulated displacement was built, and Young's modulus of each soil layer was obtained through back-analysis. The relationship between m value and Young's modulus was derived by the elastic foundation beam method, and thereby m value of each soil layer was obtained. The research results provided a certain theoretical basis for reasonable determination of design parameters of foundation pit, and has important practical significance for the effective control of the displacement and deformation of foundation pits.

河南省高等学校“专业综合改革试点”项目